Modification of Bacterial Nanocellulose Using Nonthermal Plasma-Assisted Enzymatic Hydrolysis

This study explored the structural modification of bacterial cellulose (BC) through enzymatic hydrolysis using varying cellulase activities and substrate concentrations. Optimal hydrolysis conditions (50 U/g of BC; 20 g/L of BC) were established to balance recovery and homogeneity (yielding BNC1). Hydrolysis was further combined with nonthermal plasma by suspending BC into plasma-activated water (PAW) prior to hydrolysis (BNC2). In another approach, BC suspensions were pretreated using a plasma bubble reactor followed by hydrolysis (BNC3). BNC1 and BNC2 yields were similar (∼50%), suggesting that PAW regulated the pH during hydrolysis. BNC3 yield was significantly higher (78%) compared to BNC1, indicating that the generated radicals promoted chain modifications while minimizing glucose/cellobiose release. That dual approach led to BC defibrillation, as revealed by AFM/cryo-TEM. The reduction in melting temperature observed was correlated with a crystallinity drop. Dual enzymatic and plasma-assisted strategies offer novel-intriguing avenues to fine-tune the properties of cellulose nanocomposites for sustainable applications.